---
title: "randomBytes( int ) | Grafana k6 documentation"
description: "randomBytes."
---

> For a curated documentation index, see [llms.txt](/llms.txt). For the complete documentation index, see [llms-full.txt](/llms-full.txt).

# randomBytes( int )

> Note
> 
> A module with a better and standard API exists.
> 
> The [crypto module](/docs/k6/latest/javascript-api/crypto/) partially implements the [WebCrypto API](https://www.w3.org/TR/WebCryptoAPI/), supporting more features than [k6/crypto](/docs/k6/latest/javascript-api/k6-crypto/).

Return an ArrayBuffer object with a number of cryptographically random bytes. It will either return exactly the amount of bytes requested or will throw an exception if something went wrong.

Expand table

| Parameter | Type    | Description                             |
|-----------|---------|-----------------------------------------|
| int       | integer | The length of the returned ArrayBuffer. |

### Returns

Expand table

| Type        | Description                                         |
|-------------|-----------------------------------------------------|
| ArrayBuffer | An ArrayBuffer with cryptographically random bytes. |

### Example

JavaScript ![Copy code to clipboard](/media/images/icons/icon-copy-small-2.svg) Copy

```javascript
import crypto from 'k6/crypto';

export default function () {
  const bytes = crypto.randomBytes(42);
  const view = new Uint8Array(bytes);
  console.log(view); // 156,71,245,191,56,...
}
```